Improvements in windsurfing boards

Abstract

A windsurfing board with a hull, a mast and a wishbone or other spar for winging out the sail has side fin plates with lower stabilizing faces and an adjustment system for steplessly changing the level of such fin plates, or only producing two positions of adjustment so that such fin plates are under or clear of the water. The lower position under the water is designed for producing better planing properties of the windsurfer while the top position is used for sailing under only a light wind.

I claim: 
     
       1. In a windsurfing board comprising a surfboard-like hull, means for joining a sail to the hull, fin plate means with stabilizing faces on at least two sides and the stern part of said hull, and single foot operated adjusting means for adjusting the level of said fin plate means by a person on top of the hull; wherein said fin plate means are substantially horizontal when viewed in the direction normal to a median line of said hull and form a smooth-unbroken outline with said hull; and   wherein said adjustment means has a lever extending upwardly through a portion of said hull; said adjusting means further has two limiting end positions, an upper position for placing the fin plate means above the water line in a loaded condition and a lower position for placing the fin plate means below the water line, thereby enabling the hull shape to be changed between a displacement hull and a gliding hull.   
     
     
       2. The windsurfing board as claimed in claim 1, wherein the hull is designed as a displacement hull. 
     
     
       3. The windsurfing board as claimed in claim 1, wherein said fin plate means are designed for stretching as far as the bows part of said hull. 
     
     
       4. The windsurfing board as claimed in claim 1, wherein said fin plate means are hinged to the bows part of the hull. 
     
     
       5. The windsurfing board as claimed in claim 1, wherein said fin plate means are molded onto synthetic resin of the hull for forming a single-piece bendable structure in the bows part of the hull. 
     
     
       6. The windsurfing board as claimed in claim 1, wherein the fin plate means have an outline smoothly joining the outline of the bows. 
     
     
       7. The windsurfing board as claimed in claim 1, having a foot-worked part for operation of said adjusting means, said foot-worked part being free of outwardly running edges. 
     
     
       8. The windsurfing board as claimed in claim 1 having the said adjusting means at least in the stern part of the hull. 
     
     
       9. The windsurfing board as claimed in claim 8 having a further adjusting means of the same sort placed to the fore of the means for joining a sail to the hull, for bending the fin plate means. 
     
     
       10. The windsurfing board as claimed in claim 1, wherein said adjusting means has two limiting upper and lowermost end positions answering to an optimum line of bending of said fin plate means. 
     
     
       11. The windsurfing board as claimed in claim 1 wherein said adjusting means has two dead center positions past which it is moved on changing the fin plate into the upper and lower positions, such motion past such dead center points giving a self-locking effect. 
     
     
       12. The windsurfing board as claimed in claim 1, wherein stepless adjustment of said adjusting means is possible. 
     
     
       13. The windsurfing board as claimed in claim 1, wherein said adjustment system is designed as a crank. 
     
     
       14. The windsurfing board as claimed in claim 1, wherein said adjusting means is designed with a plate. 
     
     
       15. The windsurfing board as claimed in claim 1 wherein said fin plate means have lower faces which are angled in cross-section like a bilge keel cross-section for the full length of the fin plate means. 
     
     
       16. In a windsurfing board comprising a surfboard-like hull, means for joining a sail to the hull, fin plate means with stabilizing faces on at least two sides and a stern part of said hull and a foot operated adjusting means for adjusting the level of said fin plate means by a person on top of the hull; wherein said fin plate means are substantially horizontal when viewed in the direction normal to a median line of said hull, form a smooth-unbroken outline with said hull and extend from the bow tip of said hull to the stern of the hull; and   wherein said adjusting means has two limiting end positions, an upper position for placing the fin plate means above the water line in a loaded condition and a lower position for placing the fin plate means below the water line, thereby enabling the hull shape to be changed between a displacement hull and a gliding hull.   
     
     
       17. The windsurfing board as claimed in claim 16, wherein said fin plate means are joined together at the stern of the hull by a cross-piece.